Traditional utilization of bamboo in the Central Siwalik region, Nepal

Bamboo are the fastest growing perennial woody grasses that have versatile applications. Most of the local people inhabiting the riverine area of the Siwalik region of Nepal rely on bamboo products for economic benefits and medicinal uses. Our objective was to identify the diversity of bamboo species, their ethnomedicinal practices, and economic and ecological importance. Data were collected by direct observation, key informant interviews, participatory rural appraisal, inventory technique, focus group discussions, and a household survey using semi-structured and structured questionnaires. We recorded four genera and nine species of bamboo, of which eight species have been used for agriculture, five for medicine, four for construction, food, fodder, artifacts and religious purpose, three for river embankment, and two for ornamental purpose. As the local people in the study area were deprived of medical facilities, using traditional herbal medicine to cure various diseases was a common practice. The inhabitants responded that they use bamboo-based primary ethnomedicinal care even against snake and scorpion bites. Similarly, they use bamboo young culm for reducing body weight and control diabetes. The value of the informant consensus factor was found to be maximum for the bamboo against snake and scorpion bites (1.0) and minimum for weight loss (0.81). This study concludes that the traditional utilization of all kinds of bamboo in the region is vast despite their less diversity. The recorded bamboo species are used not only for food and fodder but also in preparing artifacts, soil nutrients restoration in the fallow land, construction materials for the rural people, river embankments, and religious and spiritual purposes. Therefore, if grown on a large scale, bamboo can provide sustainable benefits for the local users and ecological aspects. Bambusa tulda and Dendrocalamus strictus have a broad spectrum of pharmacological agents. Considering the multifaceted application of bamboo in the Siwalik area, it is worthwhile to encourage the local people to bamboo plantation, which would contribute to supplement their household requirements and be one of the alternative livelihood options.


Introduction
Bamboo are ancient woody grasses and major non-timber forest products (NTFPs) that belong to the subfamily Bambusoideae of the grass family Poaceae [1].They are found in the tropical, subtropical and temperate zones and are widely planted on private lands [2].There are 121 genera and 1,662 species of bamboo in the world [3], of which Nepal harbours 23 genera and 81 species [4].Bamboo popularly known as the "Green Gold of the forest" because of their varied applications [5].They are equally important in the conservation of soil, water, and biodiversity and in the promotion of local and world economy as well [6].The bamboo rhizosphere is a vital source of plant growth-promoting rhizobacteria (PGPR) [7] and a good source for sustainable bioenergy production through microbial fuel cells [8].
The history regarding the use of bamboo is intricately associated with humans from the time immemorial.According to Hinduism, Lord Krishna is associated with bamboo as he was fond of playinga flute made of bamboo [9].Evidence shows that even Buddhist Monks carried bamboo seeds when they went to Japan from India with the aim to popularize Buddhism [10].Owing to their expanding range of uses, bamboo have transformed from being known as "poor man's trees" to "high-tech industrial raw materials" [11].They have colossal use in construction, paper industries, scaffolding, agricultural farming, diesel, food, fodder, and preparation of musical instruments, medicines, aphrodisiacs, and varieties of household artifacts [12][13][14].They have a higher raw material output than trees and high-profiting renewable resources [15].Bamboo are characterized by low weight, tensile and compressive strength, elasticity and resistibility to physical damage, and can be harvested earlier (within 3-5 years) than trees which have potential usage only after 10-30 years [16].According to Embaye et al. [17], industrial application of bamboo directly enhances the provision of income, food, survival and standard of livelihood for over 2.5 billion people worldwide.They have considerable potential as a wood substitute because they grow rapidly, and are over 20 times more sustainable in terms of their mechanical properties than timber, steel, and concrete [18].Bamboo are also important entities of several natural and agricultural ecosystem services [19] and contribute to alleviating social and environmental problems in the developing world [18].
Developing bamboo resources as an eco-friendly raw material can help alleviate poverty, generate employment, and sustain rural livelihood [20].Bamboo, an important component of the rural farming system of Tarai and Midhills of Nepal, serve as an alternate source of income as people are benefited from bamboo artifacts, fodder, fuel wood, construction materials, religious applications, and bamboo shoots used as vegetable and pickle [21].Bamboo shoots have a long history of being used as a source of both food and medicine in China and Southeast Asia [22].China is the richest country in bamboo resources, and Southeastern China alone accounts for 2/3 rd of the shoot yield and consumes more than 3/4 th of the total bamboo shoots produced [23].The bamboo shoots are consumed in raw, canned, boiled, marinated, fermented, frozen, liquid, and medicinal forms [19] and can be processed into various beverages and medicines [24].The medicinal property of bamboo, due to the presence of phytosterols and phenolic compounds, reportedly cures cardiovascular diseases, cancer, osteoarthritis, and osteoporosis [25].The young shoots are rich in proteins, carbohydrates, minerals, fiber, and low in fat and sugars, improving appetite and digestion, and help in weight loss [26].Thus, bamboo has also been drawing the attention of both health advocates and scientists worldwide.
Despite the established multiple benefits of bamboo, very few works have addressed the species diversity and economic importance of bamboo in the context of Nepal.Previous researches from Nepal have focused on the socioeconomic aspects of bamboo [27][28][29][30][31], its market potential [32], and extraction of phytohormone from bamboo seedlings [33].To the extent of our literature search, the economic importance of bamboo was enumerated from only two partsof the country-Lalitpur and Rautahat [31,32] and thus lacks significant utility regarding phytochemical and ethnobotanical importance of bamboo in Nepal.Therefore, this study aimed to identify the species diversity of bamboo, their traditional utilization, ethnomedicinal practices, and the economic importance in the central Siwalik region of Nepal.This study has also discussed the future prospects of bamboo to strengthen the alternative livelihood options for the local users.

Ethical approval
The study was conducted in the Central Siwalik Region of Nepal.The President Chure Tarai Madhesh Conservation and Development Board (PCTMCDB), Khumaltar, Lalitpur, Nepal, had already taken consent from the district authority to organize a field-based study in the seven districts of the study area.Besides this, informed consent was taken from the local community authority to grant permission for field visits and a round of questionnaire survey in every sampling site of each district selected for the study.During the field visit, the importance of the study was described to all the stakeholders by organizing a community-based meeting.Additionally, for the questionnaire survey, verbal consent was obtained from the selected respondents and the field assistants at the witness of the community authority and other responsible persons.None of the children were involved in this study.The respondents were also informed that they could withdraw their consent at any time during the study period.

Study area
This study was carried out in seven districts (Udaypur, Saptari, Siraha, Dhanusha, Mahottari, Sarlahi and Sindhuli) situated within the central Siwalik region of Nepal (Fig 1).Siwalik region, also popularly known as Chure or Churia, the youngest hills formed by depositing river products around 40 million years ago, extends from the Indus river of Pakistan in the West to Brahmaputra river of India in the East.About 12.78% of the total land of Nepal lies in the Siwalik region [34].The Siwalik land is geographically very rugged, soft, and unstable, consisting of tertiary unconsolidated and highly erodible fluvial sediments [35].In this region, the temperature varies from 28.4˚C to 35.9˚C in June and from 5˚C to 11.10˚C in January [36].Various ethnic communities like Dome, Mushahar, Majhi, Kumal, Tamang, Magar, Chhetri, and Brahman are dominant in this region.

Ethno-ecological and household survey technique
This research is the outcome of two-years field survey (2016-2018).The site selection was based on the priority made by PCTMCDB for the sustainable conservation of the Siwalik region by bamboo plantation.The PCTMCDB Khumaltar, Lalitpur, Nepal, and Kathmandu University (KU) Dhulikhel, Kavre, Nepal signed the memorandum of understanding (MoU) explicitly mentioning the research objectives.Altogether, 210 informants (155 male and 55 female) representing different age groups from 18 ethnic communities of seven districts (Tables 1 and 2) were includedin the study.The information regarding the ethnobotanical utilization of bamboo were gathered through semi-structured and structured questionnaires.A household survey was conducted among the local residents, ethnic communities, primary traders, secondary traders, local artisan groups, local vendors and traditional medicinal practitioners.

Focus group discussion (FGD)
Focus group discussion (FGD) was conducted by following the participatory rural appraisal (PRA) method [37].FGD was organized among various local groups such as community forest user groups, women groups, forest officers, healers, traders, indigenous communities, bamboo artisan groups and immigrated communities (Fig 2F).For this purpose, structured and semistructured questionnaires (S1 Table ) were prepared following Edwards et al. [38] and forwarded to the focus groups.Altogether 35 focus group discussions were carried out (five from each district).Each group was asked about the local name of bamboo plants, parts used, forms of use, purpose of use, location, place of availability, growing condition, commercial status, harvesting methods, conservation aspect and socioeconomic status.

S.
No. 63 key informants (nine from each district) who were able to communicate their ideas, views and opinions about the utilization of bamboo and their livelihood support were included (Fig 2A -2E) for KII.The key information was obtained from various groups of people like local bamboo artisan group, farmers, healers, dhami (practitioners engaged in alleviating illness based on spiritual believes), bamboo traders, women, forest officers, and head of the immigrated and indigenous communities.

Inventory technique
Inventory technique (IT) [37,40] comprised of a collection of different bamboo specimens from the nearby sampling sites and enlisting the associated ethnobotanical knowledge.These information were collected through the identification of their local name, parts used, the purpose of use, location, growing condition, availability and conservation status since ten years (Fig 2E).At the same time, in-depth market assessments were conducted at local markets to identify the available bamboo artifacts, their market value, status and trends in use from the standpointof the purchasers and sellers.

Ranking of socioeconomic status of bamboo user groups (BUGs)
The privileged, underprivileged and deprived BUGs were identified with the help of PRA tool based on income status and land ownership criteria.All household names were written, and the participants of BUGs were asked to rank them according to the overall landholding conditions, income source, amount of saving and/or loan.The information was cross checked with the same users while they were invited in gathering with the villagers.The categories used to classify the BUGs particularly in this study have been provided in Table 3.

Plant collection, identification and preservation
The voucher specimens of bamboo for herbarium preparation were collected following the guidelines provided by PCTMCDB.Organic Farming and Natural Product Research Centre (ONRC) of School of Science, Kathmandu University led the entire fieldwork.The specimens were collected in duplicate and information regarding ethnobotanical utilization of bamboo was assembled during the field visit (Fig 3).The collected bamboo specimens were identified using the published literature [4,29,[41][42][43][44][45].The herbarium specimens were prepared according to Jain and Rao [46] and tagged with information like altitude, latitude, longitude and locality of collection.The voucher specimens of identified bamboo were deposited at ONRC.

Post-field visit authentication of bio-efficacy of selected bamboo species
After the first and second field visits were completed, the collected information was discussed with the research team, district and local level stakeholders, and bamboo experts.A brief postfield survey was carried out to gather some missing information, confirm local people's ethnomedicinal practices, and clarify and comprehend some discrepancies in the information collected during the previous visits.The ethnomedicinal properties of selected bamboo species were compared with information obtained from the ethnic communities and the review of the available literatures for all species for which information was available.

Statistical analysis
Data regarding the availability, parts used, purpose of utilization, voucher specimen number, local name and altitude were recorded and analyzed using descriptive analysis, and results were presented systematically in tabular form.Informants consensus factor (ICF) was calculated according to Heinrich et al. [47] to find out the homogeneity in the information provided

Privileged class Underprivileged class Deprived class
They are able to feed their family members throughout the year from their own agricultural production.
They are able to feed their family members for four to six month in a year from their own agricultural production.
They are unable to feed their family members for less than one month in a year from their own agricultural land.
They have enough land (Six kattha to three biga) by the informants.
Where, 'nur'-total number of use report for each disease cluster; 'nt'-total number of species used for that cluster.

Livelihood status of ethnic community of BUGs in the study sites
Agriculture is the major source of livelihood for the majority of households (92%) who mainly produce rice, wheat, maize, sugarcane and potato as the major crops.However, only 2% of the households were able to meet all their annual food requirements from their own production but for the rest of the inhabitants, the food was said to be sufficient for two months or less.To meet the food requirements during the months of food deficit, the people responded to adopt multiple coping strategies such as seasonal migration for work to the district headquarters and various parts of India, and selling collected bamboo young shoots (commonly known as tama in Nepali language) as well as bamboo artifacts.Dome, Majhi, Mushahar and Kumal people are landless and rely on bamboo and bamboo products, while in rainy season, the Majhi community depend on fishing for their daily requirements.Similarly, Tamang, Bhujel, Magar, Yadav, Mahato, Chaudhary, Chettri and Brahman, who own at least some land for agriculture, partially depend on bamboo and bamboo products.Of the total informants, 90.47% (n = 190) knew at least a single use of bamboo.

Distribution of bamboo species and pattern of ethnobotanical utilization
Among 21 genera and 81 species of bamboo distributed in various parts of the country, altogether 4 genera and 9 species of bamboo have been reported and collected from our study areas (Fig 4A -4I).
Only two bamboo species were recorded from Hadiya of Udaypur, three species each from Laxminiya of Mahottari, Naudega of Siraha and Aauribaba of Dhanusa and four each from Tikulia of Saptari, Sasapur of Sarlahi and Mathillo Ranibans of Sindhuli (Fig 5A ).
Based on the survey of local communities, it was witnessed that a variety of products were made from bamboo.This was their indigenous knowledge acquired from their seniors (Table 4).However, the number of bamboo products made per household varies considerably.There were more bamboo fencing (bei) in each household than other bamboo products.
Our study revealed that all types of bamboo were found being utilized by the local community to meet their daily requirements.The pattern of use of bamboo such as agricultural use (AU), artifacts use (ARTU), construction use (CU), fodder use (FDU), food use (FU), medicinal use (MU), ornamental use (OU), religious use (RU) and embankment use (EMBU) vary between privileged, underprivileged and deprived communities in the study sites (Fig 5B).Deprived communities lack bamboo raw materials from their own production as they do not possess their land for bamboo plantation, and therefore have to invest most of their time for searching bamboo raw materials, harvesting and transportation from distant villages.
Questionnaire survey to the informants under three categories (Table 5) revealed that the bamboo utilisation pattern was fewer in deprived communities.The houses of all the deprived people were found to be constructed exclusively from bamboo, 98.90% of them had used bamboo for making artifacts and religious purpose, 69.66% answered that they use bamboo for medicinal purposes and 52.74% used young bamboo shoot for their food.The majority of the privileged (92.85%) and under privileged (96.10%) people used bamboo for varieties of agricultural purposes.It was a common observation in all kinds of communities that more than 95% of them use bamboo for various religious purposes.As the privileged and under privileged people have their own land, they use bamboo for several agricultural purposes, construction of embankment to mitigate the damage of their agricultural field from flood and landslide, and fodder to feed their cattle.Moreover, the plantation of ornamental bamboo in the courtyard and use of bamboo artifacts for decoration in the houses of privileged and under privileged people was found to be a common trend.
Respondents in the study area use bamboo species to meet their daily basic requirements.According to local bamboo artisan groups (Fig 6A -6H), they select certain types of bamboo depending on what kind of artifacts they need to prepare.The majority of bamboo species (eight species) in our study sites were utilised for agricultural purposes except A. patellaris, which is mainly used for fodder for goat and cattle because this species has thin culm with small branches and large leaves.
Regarding the uses of bamboo-based on their age, the bamboo less than one year age (young bamboo shoot i.e. tama) is mostly used for vegetables, pickles and preparation of local alcoholic beverages by fermentation.Varieties of artifacts are prepared by the bamboo artisan groups from the bamboo splits (choya) produced from the bamboo of the age group 1-3 years, and various weaving materials, bamboo sticks (for driving animals and walking), dhungro, ghiri, dustbins are prepared from bamboo of four to seven years of age.Most of the agricultural uses of bamboo for making fencing around the crop field are obtained from mature bamboo of the age group four to seven years.The bamboo of more than seven years are considered very strong and they are used for the construction of houses, furniture, fencing and embankment.Similarly, the dead culms are used as firewood and charcoal (Table 6).

Bamboo used as medicines
In response to the question regarding the prevalent diseases in study areas, key informants responded that dysentery, diarrhoea, jaundice, typhoid, gastritis, hypertension, and diabetes are common diseases in their communities.Besides these, snake and scorpion bites arecommon experiences of the local people, especially during the summer.According to the responses to the questionnaires about traditional medicinal practices, they were found using certain species of bamboo (B.bambos, B. tulda, B. nutans subsp.cupulata, D. strictus, B. nepalensis and B. balcooa) in addition to other common medicinal plants.About 70.0% of the respondents from deprived communities use bamboo for medicines, 27.27% of the respondents from underprivileged and 9.52% from privileged communities mentioned the uses of bamboo as an antiseptic and healing agent for external injuries in the human body.Hairs of culm sheath of D. strictus, B. nutans subsp.cupulata, B. balcooa and B. tulda are used to make powder to be applied externally on freshcuts and wounds (Table 7).A local healer from Sarlahi (Mr. Jogbahadur Moktan, age 54 in personal conversation) replied that he got this knowledge from his father, and he believed this practice has been proved by applying powder of hairs of bamboo culm sheath around the injured portion.However, this information was not found in other study sites.Collected bamboo sap in the inter-nodal region (commonly known as bansko dhungra ko paani) of B. nutans subsp.cupulata and B. tulda is used to cure the nocturnal enuresis (bed wetting) as well as jaundice.The decoction of a young shoot of B. bambos is used to cure sores and that of D. strictus, B. nepalensis is known to be a good tonic for cough and respiratory disorders.
Young culms (locally known as tama;   (Continued ) The level of informant agreement was high for most of the use categories (mean ICF = 0.92), and a total consensus was observed in the use of bamboo against snake and scorpion bites, while it was the lowest level (0.81) for the application of bamboo in reducing weight loss (Table 8).

Bamboo multipurpose uses as food, fodder and fuel
Since ancient times, bamboo have been used as food for human beings and fodder for livestock,considering the high nutritional value of young culms and their leaves.In our study sites,  ) are used to prepare curry, soup, pickle, condiment (chatni), and the Majhi people prepare traditional curry of young culm as well as fermented slices mixed with pork, buff, chicken, fish and egg which is famous as tama curry (Fig 7A -7E).The sheaths of young bamboo shoots are removed, the white part is cleaned, cut into thin slices and boiled in water with small amounts of wooden ash, rinsed with clean cold water to remove bitter content, sun-dried on bamboo woven baskets (supli), and mixed with oil, turmeric powder and salt (Fig 8).It is then placed in air-tight containers in a dry place mostly in sunny area, to fasten the fermentation rate.Boiled and dried fermented bamboo shoots can be stored for two years.The culm, rhizome, sheath and branches of naturally dead or broken or distorted bamboo are used as firewood.

Bamboo multipurpose uses as construction materials
From KII and FGD, it has been understood that bamboo are common sustainable resources for construction materials.In deprived communities, bamboo culms have been used for home materials such as wall, roof, flooring, door, window (jyaphri), and poles (Fig 9

Bamboo multipurpose uses in various agricultural purposes
During the household survey and participant observation, we found that three bamboo species are used for agricultural purposes.These included the construction of the greenhouse for vegetable farming (Fig 10A -10E), preparation of bei (circular fencing around the plant), poultry farms, pig farms, fencing and support for climbing and creeping agricultural and ornamental

Bamboo multipurpose uses as artifacts
Bamboo artifacts and mandro (Woven mats) are traditional products in Dome, Majhi and Mushahar communities of our study sites.They have adopted such skills since time immemorial.These diverse products have become an indispensable part of the daily life of deprived communities.There are nearly 26 categories of bamboo artifacts (Table 9) including doko/ thunche (conical woven basket used to carry grass, stones, bricks, etc.), dhakiya (small basket), thal (plate), bansuri (flute), gamala (vase), bharyang (ladder), khat (scaffolding), supli/supo (big round plate), dali/dalo (small to large sized bamboo pot to keep grains), torungo (fish keeping basket used by fish vendors), makhara (face cover for oxen not allow them to graze while ploughing), bhakari (large woven basket up to the breast height to place harvested crops), dori (rope made from spiral coiling of bamboo splits), chalno (sieve), gidra (fish • Snake and Scorpion bite.
• Leaf paste is applied at the injured part

Bamboo usesin religious ceremonies and for ornamental purpose
The inhabitants of the study sites have diverse cultural practices.

Bamboo uses as river embankment and othere cological purpose
Three species of bamboo (B.balcooa, B. tulda and B. nutans subsp.cupulata) are grown by the privileged and underprivileged communities for the establishment of the river embankment

Market problem
The study sites do not have the government-owned firms or private agencies to collect harvested bamboo culms and artifacts.The bamboo farmers and indigenous bamboo artisan groups were not able to obtain the proper benefit from bamboo artifacts marketing due to the intervention by brokers, middlemen and traders.The lack of bamboo entrepreneurship in

Discussion
Bamboo user groups (BUGs) were identified through focus group discussion (FGD), which is considered an appropriate tool for assessing people's perceptions of a specific area of interest.
To address our objectives and conveniently segregate data, BUGs were grouped into different strata (priviledged, underpriviledged and deprived).Bamboo shoots popularity is increasing in Asia and other markets around the world [57].We focused on variations of lore among eighteen ethnic and three bamboo artisan communities.The results provided notable information regarding the livelihood pattern, utilization aspect of bamboo, bamboo plantation, and lore of individuals in the application of bamboo resources for various purposes and market trends.Many households of deprived communities, especially bamboo artisan groups of the study sites depend upon bamboo to meet their daily requirements.Bamboos play a big part on their alternatives in livelihood options, although there has been a shortage of bamboo culms in the study sites.

Bamboo diversity and their utilization pattern
Traditional utilization pattern of various bamboo species for diverse purposes by the local people directly or indirectly contributes to the diversity of bamboo species and their management [14].During this research, we found that the majority of the species of bamboo (A.patellaris, C. latifolium, B. nutans subsp.cupulata, and B. nepalensis) are used for livestock fodder.Bamboos serve as a better alternative as supplement fodder because their leaves contain rich amounts of carbohydratesin contrast to other fodders [58].
In most Asian countries and America, fresh bamboo shoot is a trendy edible vegetable [59].In our study sites, succulent young culm of bamboo (B.nepalensis, B. balcooa and B. nutans subsp.cupulata, C. latifolium) are mostly used as fresh vegetables in various ethnic communities.A similar practice is documented in other studies.Tamang and Tamang [60] reported that tama is popular as a non-fermented vegetable curry among the ethnic group of Sikkim, India.In other parts of Nepal, bamboo shoots are fermented with turmeric and oil, and cooked with potatoes to organize an item called aalu tama.Our study also showed that Majhi community prepared local beverages from the fermented bamboo young shoot (commonly referred to as sandeko tama).It is similar to Chinese practice where the sap of young stalks is tapped during winter to make beverages [61].
The young bamboo shoots are enriched with a larger quantity ofmacronutrients like amino acids, proteins, carbohydrates, fat, and fiber compared to the fermented and canned shoots.The mineral content, namely calcium, potassium, iron, phosphorus and vitamin E,was highest in raw shoots, followed by fermented shoots.Thus, as a recommendation for food consumption, freshly harvested shoots are preferred rather than fermented shoots due to their richer nutritional content [24].
Branches and leaves of young bamboo shoots are also widely used in traditional medicines.Of the nine species of bamboo, six species were found to be used for traditional medicines (Table 7).Like in other rural communities of Nepal [62][63][64][65][66][67][68][69], the knowledge about traditional uses of bamboo and other medicinal plants in our study area is inherited from the seniors and other elders to the juniors.In many cases, such knowledge and skills are continuously transferredverbally from generation to generation; however, it remains confined to a limited group of people [70].The traditional knowledge about medicinal plants is rapidly diminishing [71] as young generations are found paying less interest towards the traditional medicinal utilization of plants [72].Parajuli [73] has underlined the utmost importance sharing and documenting the knowledge and experiences of the local people for traditional uses of plants which can contribute to economic development and genetic resource conservation.
Among the wide and diverse applications of bamboo, the artifact is one of the common scopes of bamboo application.Our study recorded 27 different artifacts application in the  Central Siwalik region.A previous study reported only 14 major uses, namely containers, pillars for shelter, drying racks, roof beams or trusses, thatch supporting lattices, fences, posts and so on in eastern Nepal [20].Comparatively, the limiteduses in eastern Nepal might be due to the inclusion of a higher sample of privileged communities and a lack of study in artifactspecific ethnic groups.Our study, on the other hand, targeted the ethnic groups Mushahar, Dome and Majhi, who still primarily rely on the bamboo artifacts for their livelihood.Traditionally, bamboo artifacts were made by individual households in the beginning, and the primary purpose of bamboo artifacts was to achieve self-sufficiency.However, during our field survey, we found that privileged and under privileged people were considerably less involved in making bamboo artifacts, which could be due to the increased use of plastic-made materials.Only deprived communities were involved for making bamboo artifacts.
During FGD and field observation, we found that B.nutans sub sp.cupulata, B. vulgaris and C. latifolium have higher cultural reverence in festivities like Chhath pooja, marriage and other traditional rituals for which people have been using bamboo for thousands of years.Traditional bamboo artifacts in our study sites usually possess rich cultural properties and extensive marketing prospects.We found that the development of traditional bamboo artifacts can be combined well with cultural inheritance and fulfilling the livelihood requirements.The longlasting foundation of cultural significance of the species can inherently prevent the depletionof the bamboo in the area.However, adaptation to the use of modern products may threaten the preservation of species for the cultural uses [74][75][76]. In

Plantation development and market trends of bamboo
During FGDs, key informant interview and direct observation, we noted that adequate knowledge ofbamboo plantation, management, and marketing were lacking amongst the local bamboo users.This finding is in agreement with Das [29], who reported that the bamboo farmers, artisan groups and traders do not have sufficient information on the technical aspectsof bamboo plantation and marketing.We also found that there is also scarcity of planting stocks for large-scale bamboo plantations in homesteads, farmlands, and fallow lands, as well as in seasonal ravines and riverine areas.Non-availability of planting stock of bamboo is the major constraint for bamboo planting because it is traditionally propagated by rhizome cutting, which is very tiresome and time-consuming, on top of that, bamboo seeds are not easily available as almost all the bamboo species flower after a long interval [79].
The most commercially marketed shoots for vegetable purposes in our study sites are B. tulda,B.balcooa,B.nepalensis and B. nutans sub sp.cupulata.In India, B. balcooa, B. bambos, B. tulda, Chimonobambusa callosa, C. hookeriana, Dendrocalamus flagellifer, D. giganteus, D. hamiltonii, D. hookeri, and Melocanna baccifera are mostly used for food [24].Over the duration of field visit, the current price ofone mature bamboo culm (mainly B. tulda, B. balcooa, B. nutans subsp.cupulata and D. strictus) increased from NRs 150 to 370 (equivalent to 1.26 to 3.12 US$) and young shoot (tama) ranges from NRs 40 to 60 (equivalent to 0.336 to0.51 US$).Our result is supported by Jha and Yadav [32], who reported that the price of bamboo culms increasing day by day in Rautahat district, Nepal.This sudden price hike suggests the scarcity of the products and the risk of unavailability followed by disappearance of the products from local communities.The survey of trade centers showed that B. nutans subsp.cupulata, B. tulda, B. balcooa and D. strictus have a huge potential to enhance the livelihood and socioeconomic development by manufacturing the artifacts that could be easily sold.After consultation with the local people, district forest office, traders and community development organizations, these species were prioritized because of their potential commercial values.However, local people were mostly unaware of the scientific plantation of thesebamboo, and the income generation through the commercialization of such species was negligible.This is one of the instances ofthe worrying trend in the consumption of bamboo, and hence, it underpins the need for plantation, conservation and management of bamboo in our study site.

Bio-efficacy, novelty and future perspectives of bamboo
The comparison of local uses and ethnomedicinal properties of six bamboo species reported from our study area showed that traditional use was coherent with known pharmacological properties.Our studies highlight the importance of bamboo in local diets and medicine but also indicate that the current trends in the harvesting of B. tulda and B. nepalensis may not be sustainable and could affect species availability in the future.The medicinal uses of bamboo by ethnic community of Central Siwalik region of Nepal needed to be reinforced with phytochemical studies in order to authenticate their bio-efficacy.This matter was raised in multiple ethnomedicinal studies, but only a few provided the required evidences [80].
The present study is the first documentation on ethnobotanical uses of nine bamboo species used by the inhabitants of Central Siwalik region of Nepal.The current ethnobotanical uses of reported bamboo species were compared with previous studies conducted in Siwalik region and other areas of Nepal [4,21,27,31,32,44,81] to find the novelty.There is scanty of reports on medicinal uses of B. balcooa, B. bambos, B. nepalensis, D. strictus and B. nutansubsp.cupulata in context of Nepal.The data collected from the study area revealed considerable differences in the plant parts and their utilization as reported from other regions.Some newly documented bamboo species used in medicinal purposes include B. balcooa, B. bambos, B. neplensis, D. strictus and B. uutans subsp.cupulata.These bamboo species with new medicinal uses could be studied further to screen bioactive compounds and their pharmacological activities.Bamboos are alternative source of forest and they have great role in conservation biology and become priority concerns.With knowledge of the awareness of the conservation biology and environment however people have to fulfill the enormous demands of the markets, they have to exploit the limited resources.

Conclusion
We have documented nine bamboo species which have potential ethnobotanical importance.Our study suggested that the bamboo species can be considered as valuable non-timber forest products which contribute significant socioeconomic impact on the livelihood of the local people.Most of the bamboo species were used for agricultural applications.However, deprived people are often away from the reach of the benefits of bamboo resources.Plantation of various species of bamboo needs to be carried out with public participation, and the establishment of bamboo refinery industry is a current demand so as to economically empower the deprived communities.The use of bamboo by deprived communities fairly influences the fulfillment of everyday necessities to the community.However, until their artifacts are considered cheap and low-quality items, the chances of improving the economic status of the bamboo artisan groups is impossible.
There is a lack of information on marketing and bamboo's demand and supply trends.Therefore, further detailed marketing appraisal is required.There is a need to develop new livelihood opportunities through bamboo plantation and establishment of bamboo industries by improving product quality and targeting high-value markets.At the same time, it is equally important for the sustainable management of existing bamboo species.Propagation of high-priority bamboo species, as mentioned in this study, in degraded and fallow land with technical assistance from the local government would be helpful to facilitate the maximum uses of bamboo, which directly augments the livelihood pattern of deprived communities.This study revealed the importance of bamboo in the traditional health care system.Pharmacological studies of traditionally used bamboo are thus an important line of research to pursue.

Fig 5 .
Fig 5. A-Total number of bamboo species in sampling sites.B-Major uses of bamboo species recorded from the study sites.https://doi.org/10.1371/journal.pone.0296886.g005

(
Fig 13A-13G) in field bunds, bench terraces, marginal lands, fallow lands, stream banks, seasonal ravines and riverbanks.About 2-3 years old culms of C. latifolium and D. strictusareused for making flag poles.The dried culms of C. latifolium and B. nutans subsp.cupulata are used to prepare sinka (very thin splits of about 20-30 cm in length) to stitch the leaves of sakhuwa/ sal (Shorea robusta), and other large leaves to prepare duna and tapari (smaller and larger leaf plates respectively; Fig 14B, 14G and 14H).These duna and tapari are most commonly used during religious ceremonies to place worship items and even for serving food at home and Nepali chulo (a traditional Nepali restaurant).Almost all the bamboo species recorded in the field are also used to make bhutuna (almost cylindrical shaped bamboo splits about one foot in length arranged in a bundle), which are common in the kitchen of the local people who use it to stir while frying corn, beans, or wheat and other cereals.We also observed 3-5 years old culm of C. latifolium also being used for fishing (Fig 14I).

Fig 10 .
Fig 10.Application of bamboo for agricultural purpose: A-Bamboo splits; B-Bamboo for climbers; C-Bamboo for preparation of nursery shed; D-Bamboo used as live fencing to prevent entry of unwanted domestic and wild animals; E and F-Bamboo in preparation of nursery for bamboo seedlings; G-Bamboo fencing around paddy field.https://doi.org/10.1371/journal.pone.0296886.g010

Fig 11 .
Fig 11.Bamboo artifacts: A-Thunche, B-Tokari being used to transport poultry, C-Tokari being used to pack mango, D-Rectangular ghum, E-Circular ghum with central hood to fit with the head of the user, F-Aakhne doko and basket used to cover chickens, G-Bamboo wall, H-Jyaphri, I-Semicircular ghum, J-A boy wearing a circular ghum, K-A bamboo rhizome being carved into an artifact, L-Dalo, M-Tokari, N-Dhakiya, O-An idol of Lord Ganesh, P-Bhakari, Q-Gidra, R-Torungo, S-Birds carved from bamboo rhizomes, T-Bamboo artifacts kept for sell in local market.https://doi.org/10.1371/journal.pone.0296886.g011 our study sites, B. balcooa, B. tulda and D. strictus have been used for the rehabilitation of degraded land as well as eco-restoration of seasonal ravines and riverine areas.The result is comparable to the study in the ecologically fragile land of northeastern hilly region of India, where B. nutans, B. arundinacea and D. hamiltonii have been usedfor eco-restoration of Jhum fallows [77].Similarly, B. bambos, B. nutans, B. pallida, D. strictus, D. hamiltonii, D. longispathus, D. hookeri, D. sikkimensis, Melocanna baccifera, Chimonabambusa callosa, Schiostachyum polymorphum, Neomicroaclamus mannii, Gigantochloa andamanica, Sinarundinaria falcate have been found to be of great potential and can effectively be used for the restoration of the degraded areas of the Meghalaya region of India [78].

Fig 14 .
Fig 14.Miscellaneous uses of bamboo: A-Lamp shed, B-Tapari (large plate made of Shorea robusta leaves stitched with thin bamboo splits (sinka) of C. latifolium, C-Sinka and duna, D-Bhutuna prepared from mature C. latifolium splits, E-A man carrying sub-branches of B. nutans subsp.cupulata for making tooth brush, F-Culm of mature (6 years old) B. tulda being used as a ladder to reach the bottom of well, G-Bauta, H-Duna, I-Bamboo culm of C. latifolium being used as fishing rod, J-Mature culms (6 years old) of B. tulda used in swing (ping) during dashain festival, K-Bei for plant protection.https://doi.org/10.1371/journal.pone.0296886.g014

Table 4 .
(Continued) *Species not recorded in Annotated Cheklist of the Flowering Plants of Nepal.WCE: Western, Central and Eastern Nepal, EC: Eastern and Central Nepal, ECMW: Eastern, Central and Mid-western Nepal, CMW: Central and Midwestern Nepal, BMKC: Bishnu Maya KC (Specimen collector); KU: Kathmandu https://doi.org/10.1371/journal.pone.0296886.t004theyoung culm (tama) of certain species of bamboo (B.nepalensis, B. balcooa and B. nutans subsp.cupulata) have been used as food for human consumption.A major vegetable is prepared from the freshly cut young shoots.The bamboo shoot slices are usually mixed with other vegetables such as potato, broad bean and lady's finger.The fermented bamboo shoots (Fig 7D ).In some cases, the local people use bamboo for making narrow cross bridges over the brooks.Mature, straight, thick and sturdy bamboo culms (B.tulda, B. balcooa, B. bambos, B. nepalensis and B. nutans subsp.cupulata) generally of more than seven years old were used as construction materials or the main pillars of traditional houses.Bambusa tulda is the most prioritized -grown bamboo species widely used in traditional household construction and other local uses.Thin bamboo with long internodes (B.nutans subsp.cupulata) is used to make a roof frame, wall, and floor mat.

Table 7 . Comparison between phytochemical properties and indigenous uses of bamboo.
bartabandha and other religious ceremonies like saptaha (worship and recitation of religious books like mahabharat, purans, etc., for seven consecutive days organized by an individual or family or community level), kulpooja (worship to the ancestors), and mandap in and nearby water bodies during chhat pooja (worship of Sun as God; Fig 12Aand 12B).Bamboo artifacts like dalo, dhakiya, supli are used to decorate, transport and offering fruits and other worship items during chhat festival.Bansuri (flute) is made from 1-3 years old culm of C. latifolium.Coffins are generally made from culm of B. nutans subsp.cupulata, B. tulda and B. balcooa.Besides these, B. vulgaris is planted in house yards forornamental purposes.